Both EEG sleep spindles and seizure discharges may be considered manifestation of widespread, bilaterally syncronous, episodic neuronal firings. Lesions of the rostral thalamus or orbital frontal cortex suppress spontaneous EEG sleep spindles in the cat. Pilot data has indicated these lesions may also suppress generalized convulsions. The propoed research would seek to verify and extend these findings. Generalized convulsions would be induced and the effects of these lesions on ongoing convulsions or seizure threshold would be evaluated. It is proposed that lesions of the rostral thalamus and orbital frontal cortex suppress synchronous discharge by altering thalamic internuclear interactions. The proposed research would gather some/preliminary electrophysiological data on this hypothesis